/
gpst.c
1290 lines (1134 loc) · 38.5 KB
/
gpst.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/*
* OpenConnect (SSL + DTLS) VPN client
*
* Copyright © 2016-2017 Daniel Lenski
*
* Author: Daniel Lenski <dlenski@gmail.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* version 2.1, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*/
#include <config.h>
#include <unistd.h>
#include <fcntl.h>
#include <time.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>
#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>
#ifndef _WIN32
#include <sys/wait.h>
#endif
#include <stdarg.h>
#ifdef HAVE_LZ4
#include <lz4.h>
#endif
#ifdef __FreeBSD__
#include <sys/types.h>
#include <netinet/in.h>
#endif
#ifdef _WIN32
#include "win32-ipicmp.h"
#else
#include <netinet/ip.h>
#include <netinet/ip_icmp.h>
#endif
#if defined(__linux__)
/* For TCP_INFO */
# include <linux/tcp.h>
#endif
#include <assert.h>
#include "openconnect-internal.h"
/*
* Data packets are encapsulated in the SSL stream as follows:
*
* 0000: Magic "\x1a\x2b\x3c\x4d"
* 0004: Big-endian EtherType (0x0800 for IPv4)
* 0006: Big-endian 16-bit length (not including 16-byte header)
* 0008: Always "\x01\0\0\0\0\0\0\0"
* 0010: data payload
*/
/* Strange initialisers here to work around GCC PR#10676 (which was
* fixed in GCC 4.6 but it takes a while for some systems to catch
* up. */
static const struct pkt dpd_pkt = {
.next = NULL,
{ .gpst.hdr = { 0x1a, 0x2b, 0x3c, 0x4d } }
};
/* similar to auth.c's xmlnode_get_text, including that *var should be freed by the caller,
but without the hackish param / %s handling that Cisco needs. And without freeing up
the old contents of *var, which is likely to lead to bugs? */
static int xmlnode_get_text(xmlNode *xml_node, const char *name, char **var)
{
char *str;
if (name && !xmlnode_is_named(xml_node, name))
return -EINVAL;
str = (char *)xmlNodeGetContent(xml_node);
if (!str)
return -ENOENT;
*var = str;
return 0;
}
/* We behave like CSTP — create a linked list in vpninfo->cstp_options
* with the strings containing the information we got from the server,
* and oc_ip_info contains const copies of those pointers.
*
* (unlike version in oncp.c, val is stolen rather than strdup'ed) */
static const char *add_option(struct openconnect_info *vpninfo, const char *opt, char *val)
{
struct oc_vpn_option *new = malloc(sizeof(*new));
if (!new)
return NULL;
new->option = strdup(opt);
if (!new->option) {
free(new);
return NULL;
}
new->value = val;
new->next = vpninfo->cstp_options;
vpninfo->cstp_options = new;
return new->value;
}
static int filter_opts(struct oc_text_buf *buf, const char *query, const char *incexc, int include)
{
const char *f, *endf, *eq;
const char *found, *comma;
for (f = query; *f; f=(*endf) ? endf+1 : endf) {
endf = strchr(f, '&') ? : f+strlen(f);
eq = strchr(f, '=');
if (!eq || eq > endf)
eq = endf;
for (found = incexc; *found; found=(*comma) ? comma+1 : comma) {
comma = strchr(found, ',') ? : found+strlen(found);
if (!strncmp(found, f, MAX(comma-found, eq-f)))
break;
}
if ((include && *found) || (!include && !*found)) {
if (buf->pos && buf->data[buf->pos-1] != '?' && buf->data[buf->pos-1] != '&')
buf_append(buf, "&");
buf_append_bytes(buf, f, (int)(endf-f));
}
}
return buf_error(buf);
}
/* Parse this JavaScript-y mess:
"var respStatus = \"Challenge|Error\";\n"
"var respMsg = \"<prompt>\";\n"
"thisForm.inputStr.value = "<inputStr>";\n"
*/
static int parse_javascript(char *buf, char **prompt, char **inputStr)
{
const char *start, *end = buf;
int status;
const char *pre_status = "var respStatus = \"",
*pre_prompt = "var respMsg = \"",
*pre_inputStr = "thisForm.inputStr.value = \"";
/* Status */
while (isspace(*end))
end++;
if (strncmp(end, pre_status, strlen(pre_status)))
goto err;
start = end+strlen(pre_status);
end = strchr(start, '\n');
if (!end || end[-1] != ';' || end[-2] != '"')
goto err;
if (!strncmp(start, "Challenge", 8)) status = 0;
else if (!strncmp(start, "Error", 5)) status = 1;
else goto err;
/* Prompt */
while (isspace(*end))
end++;
if (strncmp(end, pre_prompt, strlen(pre_prompt)))
goto err;
start = end+strlen(pre_prompt);
end = strchr(start, '\n');
if (!end || end[-1] != ';' || end[-2] != '"' || (end<start+2))
goto err;
if (prompt)
*prompt = strndup(start, end-start-2);
/* inputStr */
while (isspace(*end))
end++;
if (strncmp(end, pre_inputStr, strlen(pre_inputStr)))
goto err2;
start = end+strlen(pre_inputStr);
end = strchr(start, '\n');
if (!end || end[-1] != ';' || end[-2] != '"' || (end<start+2))
goto err2;
if (inputStr)
*inputStr = strndup(start, end-start-2);
while (isspace(*end))
end++;
if (*end != '\0')
goto err3;
return status;
err3:
if (inputStr) free(*inputStr);
err2:
if (prompt) free(*prompt);
err:
return -EINVAL;
}
int gpst_xml_or_error(struct openconnect_info *vpninfo, int result, char *response,
int (*xml_cb)(struct openconnect_info *, xmlNode *xml_node),
char **prompt, char **inputStr)
{
xmlDocPtr xml_doc;
xmlNode *xml_node;
char *err = NULL;
/* custom error code returned by /ssl-vpn/login.esp and maybe others */
if (result == -EACCES)
vpn_progress(vpninfo, PRG_ERR, _("Invalid username or password.\n"));
if (result < 0)
return result;
if (!response) {
vpn_progress(vpninfo, PRG_DEBUG,
_("Empty response from server\n"));
return -EINVAL;
}
/* is it XML? */
xml_doc = xmlReadMemory(response, strlen(response), "noname.xml", NULL,
XML_PARSE_NOERROR);
if (!xml_doc) {
/* is it Javascript? */
char *p, *i;
result = parse_javascript(response, &p, &i);
switch (result) {
case 1:
vpn_progress(vpninfo, PRG_ERR, _("%s\n"), p);
break;
case 0:
vpn_progress(vpninfo, PRG_INFO, _("Challenge: %s\n"), p);
if (prompt && inputStr) {
*prompt=p;
*inputStr=i;
return -EAGAIN;
}
break;
default:
goto bad_xml;
}
free((char *)p);
free((char *)i);
goto out;
}
xml_node = xmlDocGetRootElement(xml_doc);
/* is it <response status="error"><error>..</error></response> ? */
if (xmlnode_is_named(xml_node, "response")
&& !xmlnode_match_prop(xml_node, "status", "error")) {
for (xml_node=xml_node->children; xml_node; xml_node=xml_node->next) {
if (!xmlnode_get_text(xml_node, "error", &err))
goto out;
}
goto bad_xml;
}
/* is it <challenge><user>user.name</user><inputstr>...</inputstr><respmsg>...</respmsg></challenge> */
if (xmlnode_is_named(xml_node, "challenge")) {
for (xml_node=xml_node->children; xml_node; xml_node=xml_node->next) {
if (inputStr && xmlnode_is_named(xml_node, "inputstr"))
xmlnode_get_text(xml_node, "inputstr", inputStr);
else if (prompt && xmlnode_is_named(xml_node, "respmsg"))
xmlnode_get_text(xml_node, "respmsg", prompt);
else if (xmlnode_is_named(xml_node, "user"))
{} /* XXX: override the username passed to the next form? */
}
result = -EAGAIN;
goto out;
}
if (xml_cb)
result = xml_cb(vpninfo, xml_node);
if (result == -EINVAL) {
bad_xml:
vpn_progress(vpninfo, PRG_ERR,
_("Failed to parse server response\n"));
vpn_progress(vpninfo, PRG_DEBUG,
_("Response was:%s\n"), response);
}
out:
if (err) {
if (!strcmp(err, "GlobalProtect gateway does not exist")
|| !strcmp(err, "GlobalProtect portal does not exist")) {
vpn_progress(vpninfo, PRG_DEBUG, "%s\n", err);
result = -EEXIST;
} else if (!strcmp(err, "Invalid authentication cookie")) {
vpn_progress(vpninfo, PRG_ERR, "%s\n", err);
result = -EPERM;
} else {
vpn_progress(vpninfo, PRG_ERR, "%s\n", err);
result = -EINVAL;
}
free(err);
}
if (xml_doc)
xmlFreeDoc(xml_doc);
return result;
}
#define ESP_HEADER_SIZE (4 /* SPI */ + 4 /* sequence number */)
#define ESP_FOOTER_SIZE (1 /* pad length */ + 1 /* next header */)
#define UDP_HEADER_SIZE 8
#define TCP_HEADER_SIZE 20 /* with no options */
#define IPV4_HEADER_SIZE 20
#define IPV6_HEADER_SIZE 40
/* Based on cstp.c's calculate_mtu().
*
* With HTTPS tunnel, there are 21 bytes of overhead beyond the
* TCP MSS: 5 bytes for TLS and 16 for GPST.
*/
static int calculate_mtu(struct openconnect_info *vpninfo, int can_use_esp)
{
int mtu = vpninfo->reqmtu, base_mtu = vpninfo->basemtu;
int mss = 0;
#if defined(__linux__) && defined(TCP_INFO)
if (!mtu) {
struct tcp_info ti;
socklen_t ti_size = sizeof(ti);
if (!getsockopt(vpninfo->ssl_fd, IPPROTO_TCP, TCP_INFO,
&ti, &ti_size)) {
vpn_progress(vpninfo, PRG_DEBUG,
_("TCP_INFO rcv mss %d, snd mss %d, adv mss %d, pmtu %d\n"),
ti.tcpi_rcv_mss, ti.tcpi_snd_mss, ti.tcpi_advmss, ti.tcpi_pmtu);
if (!base_mtu) {
base_mtu = ti.tcpi_pmtu;
}
/* XXX: GlobalProtect has no mechanism to inform the server about the
* desired MTU, so could just ignore the "incoming" MSS (tcpi_rcv_mss).
*/
mss = MIN(ti.tcpi_rcv_mss, ti.tcpi_snd_mss);
}
}
#endif
#ifdef TCP_MAXSEG
if (!mtu && !mss) {
socklen_t mss_size = sizeof(mss);
if (!getsockopt(vpninfo->ssl_fd, IPPROTO_TCP, TCP_MAXSEG,
&mss, &mss_size)) {
vpn_progress(vpninfo, PRG_DEBUG, _("TCP_MAXSEG %d\n"), mss);
}
}
#endif
if (!base_mtu) {
/* Default */
base_mtu = 1406;
}
if (base_mtu < 1280)
base_mtu = 1280;
#ifdef HAVE_ESP
/* If we can use the ESP tunnel then we should pick the optimal MTU for ESP. */
if (!mtu && can_use_esp) {
/* remove ESP, UDP, IP headers from base (wire) MTU */
mtu = ( base_mtu - UDP_HEADER_SIZE - ESP_HEADER_SIZE
- 12 /* both supported algos (SHA1 and MD5) have 96-bit MAC lengths (RFC2403 and RFC2404) */
- (vpninfo->enc_key_len ? : 32) /* biggest supported IV (AES-256) */ );
if (vpninfo->peer_addr->sa_family == AF_INET6)
mtu -= IPV6_HEADER_SIZE;
else
mtu -= IPV4_HEADER_SIZE;
/* round down to a multiple of blocksize */
mtu -= mtu % (vpninfo->enc_key_len ? : 32);
/* subtract ESP footer, which is included in the payload before padding to the blocksize */
mtu -= ESP_FOOTER_SIZE;
} else
#endif
/* We are definitely using the TLS tunnel, so we should base our MTU on the TCP MSS. */
if (!mtu) {
if (mss)
mtu = mss - 21;
else {
mtu = base_mtu - TCP_HEADER_SIZE - 21;
if (vpninfo->peer_addr->sa_family == AF_INET6)
mtu -= IPV6_HEADER_SIZE;
else
mtu -= IPV4_HEADER_SIZE;
}
}
return mtu;
}
#ifdef HAVE_ESP
static int set_esp_algo(struct openconnect_info *vpninfo, const char *s, int hmac)
{
if (hmac) {
if (!strcmp(s, "sha1")) { vpninfo->esp_hmac = HMAC_SHA1; vpninfo->hmac_key_len = 20; return 0; }
if (!strcmp(s, "md5")) { vpninfo->esp_hmac = HMAC_MD5; vpninfo->hmac_key_len = 16; return 0; }
} else {
if (!strcmp(s, "aes128") || !strcmp(s, "aes-128-cbc"))
{ vpninfo->esp_enc = ENC_AES_128_CBC; vpninfo->enc_key_len = 16; return 0; }
if (!strcmp(s, "aes-256-cbc")) { vpninfo->esp_enc = ENC_AES_256_CBC; vpninfo->enc_key_len = 32; return 0; }
}
vpn_progress(vpninfo, PRG_ERR, _("Unknown ESP %s algorithm: %s"), hmac ? "MAC" : "encryption", s);
return -ENOENT;
}
static int get_key_bits(xmlNode *xml_node, unsigned char *dest)
{
int bits = -1;
xmlNode *child;
char *s, *p;
for (child = xml_node->children; child; child=child->next) {
if (xmlnode_get_text(child, "bits", &s) == 0) {
bits = atoi(s);
free(s);
} else if (xmlnode_get_text(child, "val", &s) == 0) {
for (p=s; *p && *(p+1) && (bits-=8)>=0; p+=2)
*dest++ = unhex(p);
free(s);
}
}
return (bits == 0) ? 0 : -EINVAL;
}
#endif
/* Return value:
* < 0, on error
* = 0, on success; *form is populated
*/
static int gpst_parse_config_xml(struct openconnect_info *vpninfo, xmlNode *xml_node)
{
xmlNode *member;
char *s;
int ii;
if (!xml_node || !xmlnode_is_named(xml_node, "response"))
return -EINVAL;
/* Clear old options which will be overwritten */
vpninfo->ip_info.addr = vpninfo->ip_info.netmask = NULL;
vpninfo->ip_info.addr6 = vpninfo->ip_info.netmask6 = NULL;
vpninfo->ip_info.domain = NULL;
vpninfo->ip_info.mtu = 0;
vpninfo->esp_magic = inet_addr(vpninfo->ip_info.gateway_addr);
vpninfo->esp_replay_protect = 1;
vpninfo->ssl_times.rekey_method = REKEY_NONE;
vpninfo->cstp_options = NULL;
for (ii = 0; ii < 3; ii++)
vpninfo->ip_info.dns[ii] = vpninfo->ip_info.nbns[ii] = NULL;
free_split_routes(vpninfo);
/* Parse config */
for (xml_node = xml_node->children; xml_node; xml_node=xml_node->next) {
if (!xmlnode_get_text(xml_node, "ip-address", &s))
vpninfo->ip_info.addr = add_option(vpninfo, "ipaddr", s);
else if (!xmlnode_get_text(xml_node, "netmask", &s))
vpninfo->ip_info.netmask = add_option(vpninfo, "netmask", s);
else if (!xmlnode_get_text(xml_node, "mtu", &s)) {
vpninfo->ip_info.mtu = atoi(s);
free(s);
} else if (!xmlnode_get_text(xml_node, "ssl-tunnel-url", &s)) {
free(vpninfo->urlpath);
vpninfo->urlpath = s;
if (strcmp(s, "/ssl-tunnel-connect.sslvpn"))
vpn_progress(vpninfo, PRG_INFO, _("Non-standard SSL tunnel path: %s\n"), s);
} else if (!xmlnode_get_text(xml_node, "timeout", &s)) {
int sec = atoi(s);
vpn_progress(vpninfo, PRG_INFO, _("Tunnel timeout (rekey interval) is %d minutes.\n"), sec/60);
vpninfo->ssl_times.last_rekey = time(NULL);
vpninfo->ssl_times.rekey = sec - 60;
vpninfo->ssl_times.rekey_method = REKEY_TUNNEL;
free(s);
} else if (!xmlnode_get_text(xml_node, "gw-address", &s)) {
/* As remarked in oncp.c, "this is a tunnel; having a
* gateway is meaningless." See esp_send_probes_gp for the
* gory details of what this field actually means.
*/
if (strcmp(s, vpninfo->ip_info.gateway_addr))
vpn_progress(vpninfo, PRG_DEBUG,
_("Gateway address in config XML (%s) differs from external gateway address (%s).\n"), s, vpninfo->ip_info.gateway_addr);
vpninfo->esp_magic = inet_addr(s);
free(s);
} else if (xmlnode_is_named(xml_node, "dns")) {
for (ii=0, member = xml_node->children; member && ii<3; member=member->next)
if (!xmlnode_get_text(member, "member", &s))
vpninfo->ip_info.dns[ii++] = add_option(vpninfo, "DNS", s);
} else if (xmlnode_is_named(xml_node, "wins")) {
for (ii=0, member = xml_node->children; member && ii<3; member=member->next)
if (!xmlnode_get_text(member, "member", &s))
vpninfo->ip_info.nbns[ii++] = add_option(vpninfo, "WINS", s);
} else if (xmlnode_is_named(xml_node, "dns-suffix")) {
for (ii=0, member = xml_node->children; member && ii<1; member=member->next)
if (!xmlnode_get_text(member, "member", &s)) {
vpninfo->ip_info.domain = add_option(vpninfo, "search", s);
ii++;
}
} else if (xmlnode_is_named(xml_node, "access-routes")) {
for (member = xml_node->children; member; member=member->next) {
if (!xmlnode_get_text(member, "member", &s)) {
struct oc_split_include *inc = malloc(sizeof(*inc));
if (!inc)
continue;
inc->route = add_option(vpninfo, "split-include", s);
inc->next = vpninfo->ip_info.split_includes;
vpninfo->ip_info.split_includes = inc;
}
}
} else if (xmlnode_is_named(xml_node, "ipsec")) {
#ifdef HAVE_ESP
if (vpninfo->dtls_state != DTLS_DISABLED) {
int c = (vpninfo->current_esp_in ^= 1);
vpninfo->old_esp_maxseq = vpninfo->esp_in[c^1].seq + 32;
for (member = xml_node->children; member; member=member->next) {
s = NULL;
if (!xmlnode_get_text(member, "udp-port", &s)) udp_sockaddr(vpninfo, atoi(s));
else if (!xmlnode_get_text(member, "enc-algo", &s)) set_esp_algo(vpninfo, s, 0);
else if (!xmlnode_get_text(member, "hmac-algo", &s)) set_esp_algo(vpninfo, s, 1);
else if (!xmlnode_get_text(member, "c2s-spi", &s)) vpninfo->esp_out.spi = htonl(strtoul(s, NULL, 16));
else if (!xmlnode_get_text(member, "s2c-spi", &s)) vpninfo->esp_in[c].spi = htonl(strtoul(s, NULL, 16));
else if (xmlnode_is_named(member, "ekey-c2s")) get_key_bits(member, vpninfo->esp_out.enc_key);
else if (xmlnode_is_named(member, "ekey-s2c")) get_key_bits(member, vpninfo->esp_in[c].enc_key);
else if (xmlnode_is_named(member, "akey-c2s")) get_key_bits(member, vpninfo->esp_out.hmac_key);
else if (xmlnode_is_named(member, "akey-s2c")) get_key_bits(member, vpninfo->esp_in[c].hmac_key);
else if (!xmlnode_get_text(member, "ipsec-mode", &s) && strcmp(s, "esp-tunnel"))
vpn_progress(vpninfo, PRG_ERR, _("GlobalProtect config sent ipsec-mode=%s (expected esp-tunnel)\n"), s);
free(s);
}
if (setup_esp_keys(vpninfo, 0))
vpn_progress(vpninfo, PRG_ERR, "Failed to setup ESP keys.\n");
else
/* prevent race condition between esp_mainloop() and gpst_mainloop() timers */
vpninfo->dtls_times.last_rekey = time(&vpninfo->new_dtls_started);
}
#else
vpn_progress(vpninfo, PRG_DEBUG, _("Ignoring ESP keys since ESP support not available in this build\n"));
#endif
}
}
/* No IPv6 support for SSL VPN:
* https://live.paloaltonetworks.com/t5/Learning-Articles/IPv6-Support-on-the-Palo-Alto-Networks-Firewall/ta-p/52994 */
openconnect_disable_ipv6(vpninfo);
/* Set 10-second DPD/keepalive (same as Windows client) unless
* overridden with --force-dpd */
if (!vpninfo->ssl_times.dpd)
vpninfo->ssl_times.dpd = 10;
vpninfo->ssl_times.keepalive = vpninfo->esp_ssl_fallback = vpninfo->ssl_times.dpd;
return 0;
}
static int gpst_get_config(struct openconnect_info *vpninfo)
{
char *orig_path;
int result;
struct oc_text_buf *request_body = buf_alloc();
struct oc_vpn_option *old_cstp_opts = vpninfo->cstp_options;
const char *old_addr = vpninfo->ip_info.addr, *old_netmask = vpninfo->ip_info.netmask;
const char *request_body_type = "application/x-www-form-urlencoded";
const char *method = "POST";
char *xml_buf=NULL;
/* submit getconfig request */
buf_append(request_body, "client-type=1&protocol-version=p1&app-version=3.0.1-10");
append_opt(request_body, "os-version", vpninfo->platname);
if (!strcmp(vpninfo->platname, "win"))
append_opt(request_body, "clientos", "Windows");
else
append_opt(request_body, "clientos", vpninfo->platname);
append_opt(request_body, "hmac-algo", "sha1,md5");
append_opt(request_body, "enc-algo", "aes-128-cbc,aes-256-cbc");
if (old_addr) {
append_opt(request_body, "preferred-ip", old_addr);
filter_opts(request_body, vpninfo->cookie, "preferred-ip", 0);
} else
buf_append(request_body, "&%s", vpninfo->cookie);
if ((result = buf_error(request_body)))
goto out;
orig_path = vpninfo->urlpath;
vpninfo->urlpath = strdup("ssl-vpn/getconfig.esp");
result = do_https_request(vpninfo, method, request_body_type, request_body,
&xml_buf, 0);
free(vpninfo->urlpath);
vpninfo->urlpath = orig_path;
if (result < 0)
goto pre_opt_out;
/* parse getconfig result */
result = gpst_xml_or_error(vpninfo, result, xml_buf, gpst_parse_config_xml, NULL, NULL);
if (result)
return result;
if (!vpninfo->ip_info.mtu) {
/* FIXME: GP gateway config always seems to be <mtu>0</mtu> */
char *no_esp_reason = NULL;
#ifdef HAVE_ESP
if (vpninfo->dtls_state == DTLS_DISABLED)
no_esp_reason = _("ESP disabled");
else if (vpninfo->dtls_state == DTLS_NOSECRET)
no_esp_reason = _("No ESP keys received");
#else
no_esp_reason = _("ESP support not available in this build");
#endif
vpninfo->ip_info.mtu = calculate_mtu(vpninfo, !no_esp_reason);
vpn_progress(vpninfo, PRG_ERR,
_("No MTU received. Calculated %d for %s%s\n"), vpninfo->ip_info.mtu,
no_esp_reason ? "SSL tunnel. " : "ESP tunnel", no_esp_reason ? : "");
/* return -EINVAL; */
}
if (!vpninfo->ip_info.addr) {
vpn_progress(vpninfo, PRG_ERR,
_("No IP address received. Aborting\n"));
result = -EINVAL;
goto out;
}
if (old_addr) {
if (strcmp(old_addr, vpninfo->ip_info.addr)) {
vpn_progress(vpninfo, PRG_ERR,
_("Reconnect gave different Legacy IP address (%s != %s)\n"),
vpninfo->ip_info.addr, old_addr);
result = -EINVAL;
goto out;
}
}
if (old_netmask) {
if (strcmp(old_netmask, vpninfo->ip_info.netmask)) {
vpn_progress(vpninfo, PRG_ERR,
_("Reconnect gave different Legacy IP netmask (%s != %s)\n"),
vpninfo->ip_info.netmask, old_netmask);
result = -EINVAL;
goto out;
}
}
out:
free_optlist(old_cstp_opts);
pre_opt_out:
buf_free(request_body);
free(xml_buf);
return result;
}
static int gpst_connect(struct openconnect_info *vpninfo)
{
int ret;
struct oc_text_buf *reqbuf;
const char start_tunnel[12] = "START_TUNNEL"; /* NOT zero-terminated */
char buf[256];
/* Connect to SSL VPN tunnel */
vpn_progress(vpninfo, PRG_DEBUG,
_("Connecting to HTTPS tunnel endpoint ...\n"));
ret = openconnect_open_https(vpninfo);
if (ret)
return ret;
reqbuf = buf_alloc();
buf_append(reqbuf, "GET %s?", vpninfo->urlpath);
filter_opts(reqbuf, vpninfo->cookie, "user,authcookie", 1);
buf_append(reqbuf, " HTTP/1.1\r\n\r\n");
if ((ret = buf_error(reqbuf)))
goto out;
if (vpninfo->dump_http_traffic)
dump_buf(vpninfo, '>', reqbuf->data);
vpninfo->ssl_write(vpninfo, reqbuf->data, reqbuf->pos);
if ((ret = vpninfo->ssl_read(vpninfo, buf, 12)) < 0) {
if (ret == -EINTR)
goto out;
vpn_progress(vpninfo, PRG_ERR,
_("Error fetching GET-tunnel HTTPS response.\n"));
ret = -EINVAL;
goto out;
}
if (!strncmp(buf, start_tunnel, sizeof(start_tunnel))) {
ret = 0;
} else if (ret==0) {
vpn_progress(vpninfo, PRG_ERR,
_("Gateway disconnected immediately after GET-tunnel request.\n"));
ret = -EPIPE;
} else {
if (ret==sizeof(start_tunnel)) {
ret = vpninfo->ssl_gets(vpninfo, buf+sizeof(start_tunnel), sizeof(buf)-sizeof(start_tunnel));
ret = (ret>0 ? ret : 0) + sizeof(start_tunnel);
}
vpn_progress(vpninfo, PRG_ERR,
_("Got inappropriate HTTP GET-tunnel response: %.*s\n"), ret, buf);
ret = -EINVAL;
}
if (ret < 0)
openconnect_close_https(vpninfo, 0);
else {
monitor_fd_new(vpninfo, ssl);
monitor_read_fd(vpninfo, ssl);
monitor_except_fd(vpninfo, ssl);
vpninfo->ssl_times.last_rx = vpninfo->ssl_times.last_tx = time(NULL);
/* connecting the HTTPS tunnel totally invalidates the ESP keys,
hence shutdown */
if (vpninfo->proto->udp_shutdown)
vpninfo->proto->udp_shutdown(vpninfo);
}
out:
buf_free(reqbuf);
return ret;
}
static int parse_hip_report_check(struct openconnect_info *vpninfo, xmlNode *xml_node)
{
char *s;
int result = -EINVAL;
if (!xml_node || !xmlnode_is_named(xml_node, "response"))
goto out;
for (xml_node = xml_node->children; xml_node; xml_node=xml_node->next) {
if (!xmlnode_get_text(xml_node, "hip-report-needed", &s)) {
if (!strcmp(s, "no"))
result = 0;
else if (!strcmp(s, "yes"))
result = -EAGAIN;
else
result = -EINVAL;
free(s);
goto out;
}
}
out:
return result;
}
/* Unlike CSD, the HIP security checker runs during the connection
* phase, not during the authentication phase.
*
* The HIP security checker will (probably) ask us to resubmit the
* HIP report if either of the following changes:
* - Client IP address
* - Client HIP report md5sum
*
* I'm not sure what the md5sum is computed over in the official
* client, but it doesn't really matter.
*
* We just need an identifier for the combination of the local host
* and the VPN gateway which won't change when our IP address
* or authcookie are changed.
*/
static int build_csd_token(struct openconnect_info *vpninfo)
{
struct oc_text_buf *buf;
unsigned char md5[16];
int i;
if (vpninfo->csd_token)
return 0;
vpninfo->csd_token = malloc(MD5_SIZE * 2 + 1);
if (!vpninfo->csd_token)
return -ENOMEM;
/* use cookie (excluding volatile authcookie and preferred-ip) to build md5sum */
buf = buf_alloc();
filter_opts(buf, vpninfo->cookie, "authcookie,preferred-ip", 0);
if (buf_error(buf))
goto out;
/* save as csd_token */
openconnect_md5(md5, buf->data, buf->pos);
for (i=0; i < MD5_SIZE; i++)
sprintf(&vpninfo->csd_token[i*2], "%02x", md5[i]);
out:
return buf_free(buf);
}
/* check if HIP report is needed (to ssl-vpn/hipreportcheck.esp) or submit HIP report contents (to ssl-vpn/hipreport.esp) */
static int check_or_submit_hip_report(struct openconnect_info *vpninfo, const char *report)
{
int result;
struct oc_text_buf *request_body = buf_alloc();
const char *request_body_type = "application/x-www-form-urlencoded";
const char *method = "POST";
char *xml_buf=NULL, *orig_path;
/* cookie gives us these fields: authcookie, portal, user, domain, computer, and (maybe the unnecessary) preferred-ip */
buf_append(request_body, "client-role=global-protect-full&%s", vpninfo->cookie);
append_opt(request_body, "client-ip", vpninfo->ip_info.addr);
if (report) {
/* XML report contains many characters requiring URL-encoding (%xx) */
buf_ensure_space(request_body, strlen(report)*3);
append_opt(request_body, "report", report);
} else {
result = build_csd_token(vpninfo);
if (result)
goto out;
append_opt(request_body, "md5", vpninfo->csd_token);
}
if ((result = buf_error(request_body)))
goto out;
orig_path = vpninfo->urlpath;
vpninfo->urlpath = strdup(report ? "ssl-vpn/hipreport.esp" : "ssl-vpn/hipreportcheck.esp");
result = do_https_request(vpninfo, method, request_body_type, request_body,
&xml_buf, 0);
free(vpninfo->urlpath);
vpninfo->urlpath = orig_path;
result = gpst_xml_or_error(vpninfo, result, xml_buf, report ? NULL : parse_hip_report_check, NULL, NULL);
out:
buf_free(request_body);
free(xml_buf);
return result;
}
static int run_hip_script(struct openconnect_info *vpninfo)
{
#if !defined(_WIN32) && !defined(__native_client__)
int pipefd[2];
int ret;
pid_t child;
#endif
if (!vpninfo->csd_wrapper) {
vpn_progress(vpninfo, PRG_ERR,
_("WARNING: Server asked us to submit HIP report with md5sum %s.\n"
"VPN connectivity may be disabled or limited without HIP report submission.\n"
"You need to provide a --csd-wrapper argument with the HIP report submission script.\n"),
vpninfo->csd_token);
/* XXX: Many GlobalProtect VPNs work fine despite allegedly requiring HIP report submission */
return 0;
}
#if defined(_WIN32) || defined(__native_client__)
vpn_progress(vpninfo, PRG_ERR,
_("Error: Running the 'HIP Report' script on this platform is not yet implemented.\n"));
return -EPERM;
#else
if (pipe(pipefd) == -1)
goto out;
child = fork();
if (child == -1) {
goto out;
} else if (child > 0) {
/* in parent: read report from child */
struct oc_text_buf *report_buf = buf_alloc();
char b[256];
int i, status;
close(pipefd[1]);
buf_truncate(report_buf);
while ((i = read(pipefd[0], b, sizeof(b))) > 0)
buf_append_bytes(report_buf, b, i);
waitpid(child, &status, 0);
if (status != 0) {
vpn_progress(vpninfo, PRG_ERR,
_("HIP script returned non-zero status: %d\n"), status);
ret = -EINVAL;
} else {
ret = check_or_submit_hip_report(vpninfo, report_buf->data);
if (ret < 0)
vpn_progress(vpninfo, PRG_ERR, _("HIP report submission failed.\n"));
else {
vpn_progress(vpninfo, PRG_INFO, _("HIP report submitted successfully.\n"));
ret = 0;
}
}
buf_free(report_buf);
return ret;
} else {
/* in child: run HIP script */
char *hip_argv[32];
int i = 0;
close(pipefd[0]);
dup2(pipefd[1], 1);
hip_argv[i++] = openconnect_utf8_to_legacy(vpninfo, vpninfo->csd_wrapper);
hip_argv[i++] = (char *)"--cookie";
hip_argv[i++] = vpninfo->cookie;
hip_argv[i++] = (char *)"--client-ip";
hip_argv[i++] = (char *)vpninfo->ip_info.addr;
hip_argv[i++] = (char *)"--md5";
hip_argv[i++] = vpninfo->csd_token;
hip_argv[i++] = NULL;
execv(hip_argv[0], hip_argv);
out:
vpn_progress(vpninfo, PRG_ERR,
_("Failed to exec HIP script %s\n"), hip_argv[0]);
exit(1);
}
#endif /* !_WIN32 && !__native_client__ */
}
int gpst_setup(struct openconnect_info *vpninfo)
{
int ret;
/* ESP keys are invalid as soon as we (re-)fetch the configuration, hence shutdown */
if (vpninfo->proto->udp_shutdown)
vpninfo->proto->udp_shutdown(vpninfo);
/* Get configuration */
ret = gpst_get_config(vpninfo);
if (ret)
goto out;
/* Check HIP */
ret = check_or_submit_hip_report(vpninfo, NULL);
if (ret == -EAGAIN) {
vpn_progress(vpninfo, PRG_DEBUG,
_("Gateway says HIP report submission is needed.\n"));
ret = run_hip_script(vpninfo);
if (ret != 0)
goto out;
} else if (ret == 0)
vpn_progress(vpninfo, PRG_DEBUG,
_("Gateway says no HIP report submission is needed.\n"));
/* We do NOT actually start the HTTPS tunnel yet if we want to
* use ESP, because the ESP tunnel won't work if the HTTPS tunnel
* is connected! >:-(
*/
if (vpninfo->dtls_state == DTLS_DISABLED || vpninfo->dtls_state == DTLS_NOSECRET)
ret = gpst_connect(vpninfo);
out:
return ret;
}
int gpst_mainloop(struct openconnect_info *vpninfo, int *timeout)
{
int ret;
int work_done = 0;
uint16_t ethertype;
uint32_t one, zero, magic;
/* Starting the HTTPS tunnel kills ESP, so we avoid starting
* it if the ESP tunnel is connected or connecting.
*/
switch (vpninfo->dtls_state) {
case DTLS_CONNECTING:
openconnect_close_https(vpninfo, 0); /* don't keep stale HTTPS socket */
vpn_progress(vpninfo, PRG_INFO,
_("ESP tunnel connected; exiting HTTPS mainloop.\n"));
vpninfo->dtls_state = DTLS_CONNECTED;
/* fall through */
case DTLS_CONNECTED:
/* Rekey if needed */
if (keepalive_action(&vpninfo->ssl_times, timeout) == KA_REKEY)
goto do_rekey;
return 0;
case DTLS_SECRET:
case DTLS_SLEEPING:
if (!ka_check_deadline(timeout, time(NULL), vpninfo->new_dtls_started + 5)) {
/* Allow 5 seconds after configuration for ESP to start */
return 0;
} else {
/* ... before we switch to HTTPS instead */
vpn_progress(vpninfo, PRG_ERR,
_("Failed to connect ESP tunnel; using HTTPS instead.\n"));
if (gpst_connect(vpninfo)) {
vpninfo->quit_reason = "GPST connect failed";
return 1;
}
}